Recently, reports of adverse reactions to hepatitis B vaccination in newborns have received wide public attention, and many people have questioned the rationality of administering the vaccine within 24 hours. Mother-to-child transmission is an important way for hepatitis B virus infection to occur, and the earlier the infection occurs, the higher the percentage of morbidity. In the case of double-positive mothers, only 4% of newborns vaccinated with hepatitis B vaccine within 24 hours fail to block the virus. If the vaccine is delayed beyond 24 hours, the chance of not blocking the virus increases to 20%, which is five times the risk. It has been shown that the younger the age of infection with the hepatitis B virus, the higher the chance of chronicity and the more difficult it is to clear the virus. For HBV-DNA-positive mothers, it is important to keep their children up-to-date with Hepatitis B immunoglobulin and Hepatitis B vaccine as required to keep their babies as free from infection as possible.